Akap1 deficiency exacerbates diabetic cardiomyopathy in mice by NDUFS1-mediated mitochondrial dysfunction and apoptosis
Akap1 deficiency exacerbates diabetic cardiomyopathy in mice by NDUFS1-mediated mitochondrial dysfunction and apoptosis
复制标题
Akap1 缺陷通过 NDUFS1 介导的线粒体功能障碍和细胞凋亡加剧小鼠糖尿病心肌病
DOI：
10.1007/s00125-020-05103-w
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发表时间：
2020-02-19
期刊：
影响因子：
8.2
通讯作者：
Ji, Lele
中科院分区：
文献类型：
--
作者：
Qi, Bingchao;He, Linjie;Ji, Lele
目的/假设：糖尿病心肌病的特征是氧化损伤和线粒体功能障碍增加，导致糖尿病患者心力衰竭风险增加。考虑到A激酶锚定蛋白121（AKAP 1）定位于线粒体外膜，在线粒体功能调节中起关键作用，本研究旨在探讨AKAP 1在糖尿病心肌病中的作用及其机制。将链脲佐菌素（STZ）注射到Akap 1敲除（Akap 1-KO）小鼠及其野生型（WT）同窝仔中以诱导糖尿病。此外，用高葡萄糖处理的原代新生心肌细胞被用作糖尿病的细胞模型。超声心动图评价心功能。通过注射携带Akap 1的腺相关病毒9（AAV 9-Akap 1）进行Akap 1过表达。结果：STZ诱导的糖尿病小鼠模型心肌AKAP 1表达下调。与WT糖尿病同窝出生小鼠相比，STZ处理的糖尿病小鼠中Akap 1-KO显著加重了心功能障碍，如左心室射血分数所证明（LVEF; STZ处理的WT小鼠[WT/STZ] vs STZ处理的Akap 1-KO小鼠[KO/STZ]，51.6% vs 41.6%）。从机制上讲，Akap 1缺乏会损害线粒体呼吸功能，其特征是ATP产生减少。此外，Akap 1缺陷通过增强线粒体活性氧（ROS）的产生增加心肌细胞凋亡。此外，免疫沉淀和质谱分析表明AKAP 1与NADH-泛醌氧化还原酶75 kDa亚基（NDUFS 1）相互作用。具体而言，Akap 1缺陷抑制复合物I的活动，防止易位NDUFS 1从细胞质到线粒体。Akap 1缺陷还与ATP产生减少和线粒体ROS相关凋亡增强有关。相反，STZ治疗的糖尿病小鼠心脏AKAP 1表达的恢复促进NDUFS 1向线粒体的移位，并减轻LVEF中的糖尿病心肌病。（WT/STZ注射携带gfp的腺相关病毒[AAV 9-gfp] vs WT/STZ AAV 9-Akap 1，52.4% vs 59.6%; KO/STZ AAV 9-gfp vs KO/STZ AAV 9-Akap 1，42.2% vs 57.6%）。结论/解释：我们的研究提供了第一个证据，即Akap 1缺陷通过阻碍NDUFS 1的线粒体转位以诱导线粒体功能障碍和心肌细胞凋亡而加重糖尿病心肌病。我们的研究结果表明，Akap 1上调对糖尿病患者的心肌损伤具有治疗潜力。
Aims/hypothesis:Diabetic cardiomyopathy, characterised by increased oxidative damage and mitochondrial dysfunction, contributes to the increased risk of heart failure in individuals with diabetes. Considering that A-kinase anchoring protein 121 (AKAP1) is localised in the mitochondrial outer membrane and plays key roles in the regulation of mitochondrial function, this study aimed to investigate the role of AKAP1 in diabetic cardiomyopathy and explore its underlying mechanisms.Methods:Loss- and gain-of-function approaches were used to investigate the role of AKAP1 in diabetic cardiomyopathy. Streptozotocin (STZ) was injected into Akap1-knockout (Akap1-KO) mice and their wild-type (WT) littermates to induce diabetes. In addition, primary neonatal cardiomyocytes treated with high glucose were used as a cell model of diabetes. Cardiac function was assessed with echocardiography. Akap1 overexpression was conducted by injecting adeno-associated virus 9 carrying Akap1 (AAV9-Akap1). LC-MS/MS analysis and functional experiments were used to explore underlying molecular mechanisms.Results:AKAP1 was downregulated in the hearts of STZ-induced diabetic mouse models. Akap1-KO significantly aggravated cardiac dysfunction in the STZ-treated diabetic mice when compared with WT diabetic littermates, as evidenced by the left ventricular ejection fraction (LVEF; STZ-treated WT mice [WT/STZ] vs STZ-treated Akap1-KO mice [KO/STZ], 51.6% vs 41.6%). Mechanistically, Akap1 deficiency impaired mitochondrial respiratory function characterised by reduced ATP production. Additionally, Akap1 deficiency increased cardiomyocyte apoptosis via enhanced mitochondrial reactive oxygen species (ROS) production. Furthermore, immunoprecipitation and mass spectrometry analysis indicated that AKAP1 interacted with the NADH-ubiquinone oxidoreductase 75 kDa subunit (NDUFS1). Specifically, Akap1 deficiency inhibited complex I activity by preventing translocation of NDUFS1 from the cytosol to mitochondria. Akap1 deficiency was also related to decreased ATP production and enhanced mitochondrial ROS-related apoptosis. In contrast, restoration of AKAP1 expression in the hearts of STZ-treated diabetic mice promoted translocation of NDUFS1 to mitochondria and alleviated diabetic cardiomyopathy in the LVEF (WT/STZ injected with adeno-associated virus carrying gfp [AAV9-gfp] vs WT/STZ AAV9-Akap1, 52.4% vs 59.6%; KO/STZ AAV9-gfp vs KO/STZ AAV9-Akap1, 42.2% vs 57.6%).Conclusions/interpretation:Our study provides the first evidence that Akap1 deficiency exacerbates diabetic cardiomyopathy by impeding mitochondrial translocation of NDUFS1 to induce mitochondrial dysfunction and cardiomyocyte apoptosis. Our findings suggest that Akap1 upregulation has therapeutic potential for myocardial injury in individuals with diabetes.